Sensing switch



Aug. 24, 1965 D. D. CALL 3,202,779

SENSING SWITCH Filed June 15, 1962 3 Sheets-Sheet l i col/Nrn I vzgnorxOBJ `Daniel ,D Ca ZZ Aug. 24, 1965 D. D. CAL.. 3,202,779

SENSING SWITCH Filed June l5, 1962 Fri 5.6.

3 Sheets-Sheet 2 if? 46; 12 12 l/ Aug. 24, 1965 D. D. CALL 3,202,779

SENS ING SWITCH Filed June 15, 1962 5 Sheets-Sheet 5 79 azz''i. @all 581 FB fp United States Patent C)` 3,292,779 SENSING SWITCH Daniel D.Call, 'Elk Grove, Ill., assigner to Bell & Howell Company, Chicago,Ill., a corporation of Illinois Filed June 1'5, 1962, Ser. No. 202,74114 Claims. (Cl. 200--61.42)

y endorsing apparatus for which it was particularly devised,

a demand has arisen for a more compact, miniaturized, more simple,faster operating, more directly responsive, more wear free and foolproofversion of such mechanism employing the flipper nger or arm principle.

In addition to uses such as in check endorsing apparatus, switches ofthis sort are well adapted for other 1 electrical control functionswhere responsiveness to serially moving members is required, and moreespecially sheet-form members, inclusive of checks, cards, record sheetsof various sorts, and the like, which must be accurately individuallysensed as they follow a predetermined path. This sensing may be forpurposes including actuating `a functioning unit such as -a checkendorser, energizing a counting mechanism, and the like. Additionally,because ofsubstantial advances in mechanical and electrical technologythat have been made, greatly increasing the speeds of response ofelectrical systems and gadgetry, and speeds at which sheet processingmachines can operate, more direct and higher speed responsiveness inswitch mechanism is desirable than has been possible withsystems'employing linkages and tripping mechanisms as heretofore.` f

It is, accordingly, an important object of the present invention toprovide a new and improved sen-sing switch construction which will meetall of the foregoing and other desirable requirements in vhighlyefficient, inexpensive form; f Y

Another object of the invention is to provide a novel sensing switchwhich, in addition to all oflits other'attributes, is adapted to beconstructed in such small and compact size as to be readily mountedinextremely limited lspace,` whereby to afford distinct advantages inmanufacturing design of associated apparatus, in keeping with the moderntrend toward compactness and miniaturization of equipment.v i

' A further object of the invention is to provide a new A andimprovedsensing switch construction which although it is rugged and long livedin service can be embodied in an unusually small and lightweight Yunit.

Still another object of `the inventionis to provide a novel flippersensing switch construction especially adaptedv for substantiallycapsular untized form.

Yet another object of the invention is to provide a novel sensing switchconstruction employing rotary liipper arm motivated meansalfordingpo'sitive, high speed step-bystep control. v

It is further an object of the invention to provide novel ysensingswitch apparatus wherein a flipper arm Vrotated switch actuating'memberand electrical signal means coact with the dual functions of notonly transmitting electrical signals responsive to the rotary movementsof the r`oi tatable member, -but also oflmaintaining the rotary memberand thereby the associated iiipper linger or arm means normally inapredetermined angular sensing disposition.

`A yet further object of the invention isto provide a new and improvedsensing switch construction which lends itself readily to various usesand speed requirements and which functions sensitively in a noveldirect-,manner and with great precision.

Other objects, features and advantages of the present invention will bereadily apparent from the following detailed description of certainpreferred embodiments taken in conjunction with the accompanyingdrawings, in which:

FIGURE 1 is a sectional elevational view of a sensing switch accordingto the present invention showing the same installed for use adjacent thepath of serially movable sheet members to be individually sensed andwith the relationship at the moment of engagement of one of the flipperarms by an advancing member;

FIGURE 2 is a View similar to FIGURE 1 but showing the relationship ofparts after the switch has been actuated by movement of the engagedipper arm by the advancing member;

Y kFIGURE 3 is another view similar to FIGURES 1 and 2 but showing athird relationship of the parts just before full cycle return oftheswitch to starting position;

FIGURE 4 is a sectional elevational detail view taken substantially onthe line IV-IV of FIGURE l;

FIGURE 5 is a sectional elevational detail view taken substantially onthe line V-V of FIGURE 1;

FIGURE 6 is a sectional elevational detail View disclosing the sameswitch unit in a slightly modified operating environment; s

FIGURE 7 is a sectional elevational view of a modified switchconstruction showing it in an operating environment;

FIGURE 8 is an enlarged sectional elevational detail view takensubstantially on the line VIII-VIII of FIG- URE 7;`

"FIGUREQ is a sectional elevational detail view taken substantially onthe line IXIX of FIGURE S; and

FIGURE 10 is a schematic illustration of utility of the switch incontrolling a counter. s.

In anexemplary form of the invention as shown in FIGURES 1-5, a sensingswitch structure 10 is constructed and arranged to be mounted on asuitable por-l tion 11 such as a guide trackmember alfording a pathofmovement for successive members `12 such as documents, cards, recordsheets, checks, etc., to be sensed. Although for illustrative purposesall of the structures have been shown on ailarge scale, in this instanceactu- 'ally in aV four to one ratio of an actual practical size portingmeans comprising a housing body 13 which is desirably molded from asuitable dielectric material such as a syntheticplastic and providedVwith a switch chamber cavity 14.0pening from one face of the housingbody.

About the open end of the switch chamber cavity 14 is provided ashallowrecessed seat 15 receptive of a cover plate 17, desirably madefrom transparent plastic sheet` material to enable inspection of theinterior of the chamber. This cover plate 17 has, for convenience inillustration been omitted in FIGURES 1-3, but is shown in FIGURES 4 and5 and may be permanently secured in place after the switch assembly hasbeen completed.

In order to facilitate attachment of the housing body 13 tothe paperpathway Vguide member 11, as byfmeans of screws 18, a thickenedattachment portion 19 is provided along one side of the chamber cavity14. This enables mounting of the switch unit 10 as close as practicableto the path of movement of the members 12 to be v Highlystablavfreerotaryy support for the l with its distal end portion within the chamberI4 is afforded by 'journalling it in la bearing bore 27 extendingthrough the base wall definingthe .chamber 14 and u., sensed, and in theillustratedexample alongside a longitudinal slot lla'in the member 11through which sensing means in the form of a flipper arm 2t) of theswitch unit is adapted to project across vth'epath of movement themembers 12 to be sensed.

Desirably, although only one flipper arm or linger projects into thepath of movement ofthe members 12 at anyone time, three of the flipperfinger arms are provided on al hub 21. spaced equidistantly, that is,120 apart. This yhub and the .flipper arms aredesirably made integrallyin `one piece from suitable sheet metalsuch Vas stainless steel.' In adesirable form, the hub 2l is of equilateral triangular outline and theflipper arms 2t) extend from the respective sides of the triangle, beingbent Irelative to the hub to be disposed in planes 90 relative to oneface ofthe hub. This provides an arrangement wherein the flipper armsZare arranged generally paddle wheel fashion with their broad sidesfacing in the direction of rotation` about the center of the hub 21 andextending tangent to a circleV described concentric with the center ofthe hub within the connes of the proximal end portions of the arms.

For rotatably mounting the'tlipperwheel on the supporting housingbody13, a shaft 22 made from suitable metal such as stainlessfsteel isprovided having adjacent to one end a stabilizing hub and spacer flange23 of a diameter to be received freely but closely Within the conlinsulating sheath 42 of respectivelead wires 43 extending through leadinlet passages afforded by the tubular sleeve rivets and attached attheir ends as by means of solder ifi to the respective leaf spring arms.

. In order to provide for the dual functions of switch operating anddetenting action, the member 3f? is desirably in the form of a camhaving its periphery coactively opposing the signal effecting means andmore particularly the spring switch arm 32. Accordingly, fthe member 3i)has its cam periphery provided withr a plurality of successive switcharm biasing projections 45 and intervening detent faces 47.V In thedirectly corotatively. coupled relationship of the shaft 22 and the cammember 30, the peripheral outline of the cam member is preferably ofequilateral triangular form with the projections 45 at the apices of thetriangle and the detent faces providing the sides of the triangle.Location of the shaft 22 is adjacent to but spaced from the back 3laslshownV in FIGURE l. This holds the shaft 22 and rfines of theproximal end portions of the flipper arms Ztl 1 (FIGS. l, 4 and 5).Attachment of the shaft hub 23 to the flipper hub 2l is convenientlyVeffected by means of a riveted or` peened over central projection 24 onthe hub 23 received through a complementaryy central aperture-Z in theflipper hub 21. r`

shaft 22 aligned external and internalrespective spacer bosses 2S and29on such wall. .The length of. the'spacerboss 2S is sufhcient to maintainan` adequatespacing of'theadljacentmedges of the flipper arms 20 fromthe housing. 13V with the opposing face ofthe attachment and spacer hubflange 23 freelyengageably opposingkthe outer end of the externalvspacer boss;

' Meansare provided whereby in the rotationof the u ishaft 22,' asmotivated by the flipper arms `2f) throughy ythe corotative hubattachment described to operateelecthereby the flipper arm wheelstationary until rotary or torque' pressure is applied toV one of theflipper arms Ztl to effect rotation.

` Disposition of thecam member 30 with respect to the flipper arms 26 issuch that'in the detenting coaction of the spring arm 32 and a face k47of the cam member one ofthe respective flipper arnrsZf) is locatedacross the path of movement of the sheet members 12 to be sensed intravelling past the sensing switch 10, so that the leading edge of themember `12 will engage and swing the flipper arm in the directionoffadvance of the member l2. Such interengagement is enhanced, andadequate swinging movement of the flipper arm 2t) is afforded to actuatethe sensing switch, by a' normal inclination of this trigger-poised .armtoward the advancing edge of the member 12. In addition, eachof the arms20 preferably has a terminalend kportion-48 angled to provide a biastoward the `advancing edge of the document member "12 and serving asaVlead-in andy engagement finger for the document edge.

combination switch operatingl and detenting member 3f) i leaf springswitch arms 3l and 32. carrying respective.

opposed electrical contacts 33 and 34; Mounting of the switch arms 3land- 32 is such that one of them, herein the arm 32 is disposed to Vbeoperatively engaged by the cam member 3.6).'

Y y In the exemplary sensing switch V10 shown, the switch. armsf31 and32 are mounted in spaced superposed relation to maintainthe contacts 33and 34 in normally separated .lopen switch relation.` VTo this end, thehousing body V13 is provided within the chamber 14 on the side thereofoppositel tothe attachment portion 19 with a pair of steppedlands orplatforms35 and 37 to which the switch'arms Bland 32 arerespectivelyiattached cantilever fashion. Attachment is effected bymeans comprising identical, i respective tubular rivets 33 extendingthrough respective bores39 through the adjacent wall of the housing body13 which iat the outer side is counterbored as at fil) andfflll toaccommodate rivets 'of as short as practicable length and also toreceive end portions of As thesheet member 12 drives against the engagedflipper armti and swings it in the direction of movement of the `sheetmember, the flipper wheel is turned to rotate. the. cam member 3f)countercloclwvise as viewed in FIG- URES l and`2 and thereby driving thecontiguousfcam projection 4S toward and against the spring contact arm32, as best visualized inFIGURE 2. ySince the switch .arm 32 is ofvsubstantial length and thus, resiliently flexible it affords onlymoderate resistance to flexure affording, in 'apracticalunit,yieldability in response to about seven grams force thrustagainst the triggering flipper arm 2li. `In order' to reducefrictional'resistance' to a tions 45 are curved on a -suitable radius.

During its arcfoffrnovement, the switch,v arm pressing cani projection'45; sufficiently depresses. the 4switch arm ,32, to effectrm engagementVof the contacts 33 and 34, with the opposing switch arm 3l affordingcushioning resilient flexure yieldability, as indicated in FIGURE `2,and pressure -reliefafter the contacts have been closed.

Thereby, en electrical circuit through the leads 43 is leadsf may beincluded comprises a suitable power supply. 49 and; a counter 5f) of anypreferred'electrically energized typeL commonly employed on machineswhere a record of the number of operationsornumber of units handledby a'machine is desired. Thus, upon closing ofl thel switch-10- throughdriving of the switch contacts, into 'closing relation by theV cammember 3l) Van electrical; Qrwit Vialnule'is supplied t0 the CounterVSi?. t0

effect recording of the fact that the switch has been actuated bymovement thereby of one of the sheet members 12. This is repeated foreach of the sheet members and thus affords `a count of the number ofsheet members handled by the associated machine in any period ofoperation.

After the flipper arm 2t) in triggering position has been swung about 80from its initial position in FIG- URE 1 to the position shown in FIGURE2; wherein it clears the motivating sheet member 12, the switch armengaging cam projection 4S moves sufficiently beyond center for thespring load reaction developed in the flexed spring arm 32 to snap thecam member 3i) and thereby the flipper arm wheel at an accelerated ratein the rotationally advancing direction so that the succeeding flipperarm 20 swings toward the opposing face of the motivating sheet member 12until the finger terminal 48 thereof engages the trailing marginalportion of the sheet member as shown in FIGURE 3 to assure instantaneousmovement of the terminal end portion of such flipper arm into the gapbetween the trailing edge of the motivating member 12 and the nextsucceeding sheet member 12, even though such gap may be quite narrow.Such ipping of the end of the arm 20 against such trailing edge of themotivating sheet member may even be accompanied by a slight deflectionof such trailing margin and thus affording further assurance -that thefinger terminal 4S will enter into sensing position with respect to theadvancing edge of the next lsucceeding sheet member 12. As this actionoccurs, the points or contacts 33 and 34 separate as shown in FIGURE 3.As soon as the flipper arm 20 leaves the trailing edge of the .member12, the next succeeding detent face 47 of the cam member 3@ is snappedby the spring action of the arm 32 into detenting coaction therewith sothat overrunning of the ipper wheel is avoided and should there not be asucceeding sheet member 12 or should the gap between such succeeding andthe preceding sheet member be unusually wide, the flipper arm 20 thathas been moved into triggering position will maintain that positionuntil the leading edge of the succeeding member 12 engages and swingsthe triggering arm to repeat the sensing cycle.

In the modification'of FIGURE 6, the same sensing yswitch 1t) isemployed but in order to adequately handle sheet members 12 which arequite thin, a retainer track guide bar or plate structure 51 is mountedin suitably ,spaced relation to the transporting face of the supportingmember 11 to provide a guideway S2 within which the advancing thin sheetmember 12 is guided to move in its plane and thus assure adequatecoaction of its leading edge with the triggering flipper arm 20 asshown. Gtherwise, it will be understood that operation of the sensingswitch 1t) is identical to that already described.

Where it is desired and practical to have the gap between the contactpoints of the switch arm substantially closer than provided by thearrangement of the switch 10, a sensing switch structure 53 as shown inFlGURES 7-9 may be employed operating on substantially the sameprinciple but embodying mechanism which reduces the switch arm throw orfleXure to effect closing of the contact points. Accordingly, the switch53 ha-s a flipper wheel structure which is substantially the same asthat employed in the sensing switch and includes a plurality, hereinthree circumferentially equally spaced iiipper arms S4 projecting from atriangular hub 55 and each provided with an angular lead-in terminalfinger flange 57.

Centrally the hub 55 is secured to the end portion of a shaft 5S byriveting over the end lof the shaft to clamp -the wheel hub against aspacer flange S9 integral on the shaft. This shaft 58 is rotatablyjournalled through rerepective opposite face wall panels 6ft of a bodymember including an integral connecting web portion 61 arranged toprovide an attachment base adapted to be secured by means such as screws62 to a supporting member 63 affording a guide path for sheet members 64to be sensed by the arms S4 successively projecting through a clearanceslot 65 in the member 63.

Completing the body of the switch member 53 is a generally U-shapeddielectric member 67 fitting snugly between the margins of the wallpanels 60 vand secured in place by means such as screws 68 threaded intothreaded bores 69 in the base member 61. This provides an enclosedhousing chamber 70 within the switch body wherein are mounted respectiveswitch arms 71 and 72 having opposed respective closely spaced switchcontact points 73 and 74. The switch arm 71 is the shorter of the armsand is mounted cantilever fashion on a stepped offsetting platformportion 75 on the connecting web portion of the housing member 67opposite the base portion 61, while the longer resiliently tiexibleswitch arm 72 is mounted on an offsetting platform step 77. It will beunderstood that since the housing portion 67 is made from a dielectricmaterial such as a suitable moldable plastic, it may conveniently betransparent.

Attachment of the switch arms 71 and 72 is effected by means of tubularsleeve rivets 78 similarly as described in connection with the switch1t), accommodating electrical lead wires 79 therethrough electricallyconnected to the switch arms as by means of solder 80. Respectivecoun-terbores 81 and 82 outwardly from the platform offsets 75 and 77accommodate the end portions of insulating sheaths 83 for the electricallead wires 79.

In the switch 53, the flipper wheel shaft 58 is mounted adjacent to themounts for the spring arms 71 and 72, and the end portion of the shaftopposite the iiipper wheel projects beyond the housing wall and hascorotatively attached therto a small gear or pinion 84 which meshes witha larger gear 8S corotatively attached to an end portion of a cam shaft87 also rotatably journalled through the wall panels 60 in suitablyspaced parallel relation to the shaft 58 `and carrying corotatively fastthereon, within the chamber 70 a switch actuating cam member 8S. In theillustrated embodiment, the gear wheel is made from a dielectricmaterial and the shaft 37 has a spacer collar flange 89 thereon betweenthe gear 85 and the adjacent housing wall 6). A spacer hub 90 on thegear 84 serves the same purpose.

In order to accommodate the small gap for closing of the switch contacts73 and 74, the cam member S8, which is also preferably made from adielectric material, is provided with twice the number of switch closingprojections 91 and detent faces 92 on its periphery as there are ipperarms 54. Thus, in the arrangement shown, there are six of theprejections 91 and of the detent faces 92 and it will be understood thatthese projections and faces coact with the longer resiliently flexibleswitch arm 72 in the same manner as the c-orresponding projections 45and detent faces 47 of the switch 10. However, because the switchactuating projections 91 project to a shorter distance relative to acircle through the centers of the detent faces than is true with respectto the three-projection cam member 30, the projections 91 depress theswitch arm 72 a correspondingly shorter distance, but ample to effectfull closing of the contacts 73 and 74 during the sweep of each of theprojections 91 cyclically against the switch arm 72.

As each of the flipper arms 54 is swung by the advancing document member64 it rotates the shaft 58 and thus the gear 84 through one-third of arevolution. By having the gear 85 in a 2-to-1 ratio to the gear 84, thegear 85 will be rotated one-sixth of a revolution and effectcorresponding revolvement of the cam 88 to advance the same by oneprojection and one detent face in each sensing cycle of operation of theswitch 53.

It will be understood that modifications and variations may be effectedwithout departing from the scope of the novel concepts of the presentinvention.

I claim as my invention:

l. In a sensing switch construction,

supporting means adapted to be disposed adjacent to the path of movementof successive members t0 Vbe sensed as they pass thereby and includingattachment structure for securing itin operative position relative tosaid path,

a shaft rotatably supported by said supporting means,

a liipper arm carried by said shaft and of a length to extend beyondsaid supporting means and to project across' said path of movement ofthe membersV so as to be engaged thereby to rotate said shaft,

electric signal effecting means carried by said supporting means,

and a member having a periphery opposed to said signal effecting meansand rotatably actuated by said shaft to operate saidsignal-effectingfmeans,

lsaid periphery of said member and said signal-effecting means coactingto maintain said rotatably actuated member and thus saidshaft and saidflipper armin a normal disposition wherein said arm projects across saidpath.

2. A sensing switch construction as delinedin claim 1 wherein saidelectrical signal effecting means includes a spring arm, and saidrotatably actuated member comprises a cam s-tructure having on saidperiphery a projection which engages and liexes said spring arm whensaid liipper arm effects rotation of said shaft, said periphery .alsohaving a detent face coacting with said spring arm to maintain saidnormal disposition.

3. In a sensing switch construction as defined in claim 1,said'rotatably actuated member having a shaft rotatably mounted on saidsupporting means, and a gear train connecting the arm-carrying shaft andsaid rotatably actu- Y ated member shaft for coordinated rotaryoperation when said arm-carrying shaft is rotated by `the `flipper arm.

4. In a sensing switch construction, Y

a supporting body defining an enclosed chamber theremeans for mountingsaid body adjacent to the Vpath of movement of a succession of membersto be sensed `as they pass thereby, Y

a shaft rotatably supported by said body, f'

a flipper wheel carried by said shaft externally of said chamberand-having a plurality of circumferentially spaced flipper arms each of:a length to extend beyond said supporting body and adapted to projectsuccessively into the path of movement of the members to be sensed so astobe engaged bythe members to rotate said shaft,

electrical signal effecting means mounted within-said chamber, l

and means actuated by said shaft in the rotation therey of for operatingsaid'signal effecting means.

5. ln a sensing switchconstruction,

a supporting body defining an enclosed chamber therein,

'means for mounting said body adjacent to the path of movement of asuccession of members to be` sensed as they pass thereby,

a shaft rotatably supported by said body,

a flipper wheel carried by said shaft externally of said chamber andhaving a plurality of circumferentially spaced flipper arms each of alength to extend beyond said supporting body and Yadapted to projectsuccessively into the path of movement of the members to'be sensed so asto be engaged Vby the members to rotatesaid shaft,

electrical signal effecting means mounted within said chamber,

said signal effecting means including a spring arm,

and a cam member directly engaging said spring arm and operativelyconnected with said shaft for rotation when the shaft is rotated by saidflipper arm elfecting means.

6. In a sensing switch construction,

a supporting body defining an enclosed chamber therein,

means for mounting said body adjacent to the path of movement of asuccession of members to be sensed asthey pass thereby,

a shaft rotatably supported by said body,

a llipper wheel carried by said shaft externally of said chamber andhaving a plurality of circumferentially spaced flipper arms each of alength to extend beyond said supporting body and adapted to projectsuccessively into the path of movement of the members to be sensed so asto be engaged by the members to rotate said shaft, electrical signaleffecting means mounted within said chamber,

said signal effecting means including a spring arm,

and a cam member directly engaging said spring arm and operativelyconnected with said shaft for rotation when the shaft isrotated by saidflipper arms for moving said spring arm to operate said signal effectingmeans,

said cam member having a series of detent faces thereon coactive withsaid spring arm to maintain the cam and thereby said shaft againstoverrunning.

7. In asensing switch construction,

a housing delining a switch chamber therein,

a pair of opposed switch contacts mounted on said housing within saidchamber and one of which is carried by a spring arm attached at one endto the housing and normally biasing said one contact away from the othercontact,

a rotary shaft mounted on said housing within said chamber and having acam member thereon engaging said spring arm,

said cam member being rotatable with the shaft and having a portionthereon acting during rotation of the cam member to liex said spring armand thereby move said one contact into closing engagement with the othercontact,

a portion of the shaft extending out of the housing,

and means carried by said portion of the shaft and engageable by anobject to be sensed to effect rotation of the shaft. p

8. In a sensing switch construction,

a housing defining a switch chamber therein,

a pair of opposed switch contacts mounted on said housing within saidchamber and one of which is carried by a spring arm attachedk at one endto the housing and normally biasing said one contact away from the othercontact,

a rotary shaft mounted on said housing within said vchamberand having acam member thereon engaging said spring arm,

said cam member being rotatable withthe shaft and having a portionthereon acting during rotation of the cam member to liex said spring armand thereby move said one contact into closing engagement with the othercontact, n

a portion of the shaft extending out of the housing,

and a sensing arm carried by said portion of the shaft and projectingbeyond the housing to be engaged by a member to be sensed for rotatingthe shaft and thus rotating the cam to actuate'said spring arm and closesaid contacts.

9. In a sensing switch construction,

a dielectric housing having means thereon for securing it to a supportadjacent to the path of movementiof a Vsuccession of 'members to besensed on the support,

said housing lhaving a switch chamber therein,

a pair of opposed electrical contacts mounted in said switch chamber,

a resiliently flexible spring arm carrying one of said contacts andnormally biasing said one contact away from the other contact intoswitch-open position,

a shaft carried by said housing and extending across said chamber,

a dielectric cam member carried corotatively by said shaft and having aseries of peripheral detent faces and intervening arm biasingprojections,

said detent faces coacting with said arm to maintain the cam and shaftnormally stationary,

and means outside of said chamber and operatively connected with saidshaft and arranged to be interposed in said path of movement to bemotivated by said members and thereby to rotate the shaft and said cammember and drive said projections to flex said arm to move said onecontact into closing relation to the other contact.

10. In a sensing switch as defined in claim 9, said means outside of thechamber for rotating the shaft comprising a plurali-ty of flipper armsmounted on and projecting laterally from the shaft, and said cam havingprojections and detent faces each corresponding in number to the flipperarms.

11. In a sensing switch construction,

dielectric means defining a housing having a switch chamber therein,

relatively offset platforms in said chamber,

respective resiliently flexible switch arms mounted cantilever fashionon said platforms in spaced relation and having on their distal endportions respective normally spaced contacts which are opposed to oneanother and normally in spaced relation,

a shaft mounted on said housing in said chamber in spaced relation toone of said arms adjacent to said contacts,

a cam corotative with said shaft and engaging said one arm,

said cam having a detent face coactive with said one arm in the spacedcontact disposition of the arms t maintain the cam and shaft in a normalat rest position and having a projection operative in the rotation ofthe cam to flex said one arm toward the other of said arms to close thecontacts,

said shaft having an end portion externally of said housing,

and a flipper arm wheel corotative on said end portion and including aflipper arm adapted to be engaged by a moving member to be sensed andswung thereby to rotate said shaft and thereby rotate said cam to drivesaid projection against said one arm to flex it and close said contacts.

12. In a sensing switch construction,

a housing defining a switch chamber,

said switch chamber having mounted therein opposed electrical contactsone of which is carried on an end portion of a spring arm attachedcantilever fashion on its opposite end portion to the housing in thechamber and normally biased to open contact position,

a rotary shaft carried by said housing in said chamber adjacent to saidarm and having a portion outside of the chamber,

a cam on said shaft having its periphery in engagement with said arm,

a flipper arm wheel carried by said portion of the shaft and havingthree flipper arms disposed 120 apart circumferentially,

said cam having a substantially triangular periphery v with threeprojections and three intervening detent faces,

said projections being successively operable in the rotation of the camto press against said arm and deflect it to move said one contact intoengagement `with the remaining contact and said detent faces beingsuccessively engageable with said arm in its biased position to retainthe cam and shaft and wheel in respective dwell positions,

said detent faces and said switch arms being relatively oriented tomaintain the arms in said dwell positions in a predetermined relation tothe housing for engagement by a relatively moving member to be sensedand to be swung thereby to rotate the shaft and the cam to drive one ofsaid projections against said switch arm and swing it intocontact-closing position,

said projections having surface contours cooperable with said switch armfor reacting to the arm bias after 80 rotation of the shaft with therespective projections in engagement with the arm to snap the cam inrotary direction and move the succeeding detent face rapidly into dwellengagement with the switch arm.

13. In a sensing switch construction,

means providing a housing having means attaching it to a support with-respect to which a succession of members to be sensed move,

said housing defining a switch chamber,

means in said chamber supporting a pair of switch contacts and includinga spring arm carrying one of the contacts and normally biasing suchcontact away from the other contact into switch-open position,

a shaft carried by the housing in said chamber and supporting acorotative cam,

said cam having a plurality of detent faces and switch arm actuatingprojections arranged to engage said spring arm successively in therotation of the cam,

a second shaft carried by the housing on a rotary axis spaced from thefirst mentioned shaft and having a portion outside of said chamber,

a gear train connecting said shafts,

and a flipper arm wheel carried by said portion of the second shaft andhaving arms of a length to project into the path of movement of themembers to be sensed,

said cam having twice the number of projections and detent faces as thenumber of arms.

14. A sensing switch construction including:

supporting means including means for mounting the same adjacent the pathof movement of a succession of members to be counted as they passthereby,

a shaft rotatably supported by said supporting means,

a flipper arm carried by said shaft and of a length adapted to projectacross the path of movement of the members so as to be engaged therebyto rotate said shaft,

electrical contact means for connection in a counteractuating electricalcircuit and supported by said supporting means,

said electrical contact means including a resiliently biased armnormally maintaining said contact means in open circuit relation,

and a cam member rotatably actuated by said shaft and having a peripheryopposed to said biased arm and functioning during rotation of the shaftby the flipper arm to operate said biased arm to close said contactmeans,

said periphery having detent means coactive with said biased armnormally to maintain the cam member and thereby the shaft in an at-restposition and to avoid overrunning of the shaft.

References Cited bythe Examiner UNITED STATES PATENTS 2,126,967 8/38Lyons 23S- 92 2,278,087 3/42 McLaughlin 235-98 2,802,914 8/57 Karkow20G-61.41 2,940,667 6/60 Hawkes 23S- 98 2,974,862 3/61 Eichorn 23S- 98BERNARD A. GILHEANY, Primary Examiner.

1. IN AW SENSING SWITCH CONSTRUCTION, SUPPORTING MEANS ADAPTED TO BEDISPOSED ADJACENT TO THE PATH OF MOVEMENT OF SUCCESSIVE MEMBERS TO BESENSED AS THEY PASS THEREBY AND INCLUDING ATTACHMENT STRUCTURE FORSECURING IT IN OPERATIVE POSITION RELATIVE TO SAID PATH, A SHAFTROTATABLY SUPPORTED BY SAID SUPPORTING MEANS, A FLIPPER ARM CARRIED BYSAID SHAFT SAND FOF A LENGTH TO EXTEND BEYOND SAID SUPPORTING MEANS ANDTO PROJECT ACROSS SAID PATH OF MOVEMENT OF THE MEMBERS SO AS TO BEENGAGED THEREBY TO ROTATE SAID SHAFT, ELECTRIC SIGNAL EFFECTING MEANSCARRIED BY SAID SUPPORTING MEANS, AND A MEMBER HAVING A PERIPHERYOPPOSED TO SAID SIGNAL EFFECTING MEANS AND ROTATABLY ACTUATED BY SAIDSHAFT TO OPERATE SAID SIGNAL-EFFECTING MEANS, SAID PERIPHERY OF SAIDMEMBER AND SAID SIGNAL-EFFECTING MEANS COACTING TO MAINTAIN SAIDROTATABLY ACTUATED MEMBER AND THUS SAID SHAFT AND SAID FLIPPER ARM IN ANORMAL DISPOSITION WHEREIN SAID ARM PROJECTS ACROSS SAID PATH.